Personally I'd want something more graceful like halting JS execution on the page and some sort of message... When I was a teen I rudely tricked a friend to lo

Personally I'd want something more graceful like halting JS execution on the page and some sort of message... When I was a teen I rudely tricked a friend to load an infinite alert() page, forcing them to kill their browser and lose some state. These days browsers don't let alerts block switching tabs or closing the offending tab, and with too frequent alerts you can check a box to block any more. It's better.